Concrete crushing tongs

Abstract

Concrete crushing tongs comprise a frame-shaped first jaw of tongs (1) and a second jaw of tongs (2) which is connected to the first jaw of tongs (1) at a pivot joint (3). The two jaws of tongs (1, 2) each comprise concrete crushing portions (13, 18) with projections (14, 19). The concrete crushing portions (13, 18) of both jaws of tongs (1, 2) each project beyond cutting edges (11, 17) of the two jaws of tongs (1, 2) in a direction towards the corresponding other jaw of tongs (2, 1). Thus, the concrete crushing function of the concrete crushing tongs is separated from the function of cutting the reinforcement.

I claim: 
     
       1. Concrete crushing tongs for cutting concrete parts having a reinforcement, said concrete crushing tongs comprising: first and second jaws;   a pivot joint for hingedly connecting said first and second jaws; and   means for providing a pivoting movement of said jaws to open and close relative to each other,   said first jaw having a frame-shaped first base body, including two side portions, a joint-side portion, and a front portion opposite to said joint-side portion, said side portions, joint-side portion and front portion defining an interior space which is formed to flare out in a direction of a closing movement of said jaws toward each other,   at least one of said two side portions, joint-side portion and front portion, having a closed cross-section enclosing a hollow space,   said first jaw further having a first cutting means comprising a first cutting edge and a first concrete crushing portion projecting beyond said first cutting edge towards said second jaw,   said second jaw having a second cutting means comprising a second cutting edge and a second concrete crushing portion projecting beyond said second cutting edge towards said first jaw,   whereby when said pivoting means forces said jaws to close together said first and second crushing portions crush said concrete part before said first and second cutting edges cooperate to cut said reinforcement, and said second jaw enters said interior space to push the crushed concrete material therethrough.   
     
     
       2. The concrete crushing tongs of claim 1, wherein said first concrete crushing portion comprises first projections and first concave portions, each first concave portion being positioned between two adjacent first projections, a further concave portion being positioned along each of the two side portions of the first jaw between said pivot joint and the first projection closest to said pivot joint, whereby a first envelope is defined by said pivot joint and tangent lines to said first concave portions, a tangent plane is defined by the pivot joint and said further concave portion, a distance between said first envelope and said first tangent plane in a direction away from said second jaw increasing with increasing distance from said joint. 
     
     
       3. The concrete crushing tongs of claim 2, wherein said second concrete crushing portion comprises second projections and second concave portions, each one of said second concave portions is positioned between two corresponding adjacent second projections, and further second concave portions are provided along lateral portions of said second jaw between the joint and said second projection closest to said joint, whereby a second envelope is defined by said joint and tangent lines to said second concave portions and a second tangent plane is defined by said pivot joint and said further second concave portion, and whereby a distance between said second envelope and said second tangent plane in a direction away from said first jaw increases with increasing distance from said joint. 
     
     
       4. The concrete crushing tongs of claim 1, wherein said first jaw is a casting and said closed cross-section of one of said portions of said first jaw is formed substantially as an outwardly directed C having a vertical portion and an upper and lower horizontally extending web with an outer portion connecting said webs. 
     
     
       5. The concrete crushing tongs of claim 1, wherein said second jaw comprises a second base body having, in a plane of a pivoting movement defined by said pivot joint, a substantially triangular portion having corners defined by said pivot joint, a link point for said means for pivoting said jaws, and a front side of said second base body opposite to said joint, said triangular portion comprising three leg portions enclosing a hole, said second jaw means having a substantially U-shaped cross-section on a side directed away from said first jaw in a plane perpendicular to a plane defined by said pivoting movement. 
     
     
       6. The concrete crushing tongs of claim 1, said frame-shaped first base body having rounded inner corners, said first concrete crushing portion being at least partially provided with a hard layer, and said second concrete crushing portion being at least partially provided with a hard layer. 
     
     
       7. The concrete crushing tongs of claim 1, wherein said first and second cutting edges each have a multi-layered construction, being welded on said first and second jaws, respectively. 
     
     
       8. The concrete crushing tongs of claim 1, wherein a first plane is defined by a pivot axis of said joint and a point on said first cutting edge, a second plane is perpendicular to said first plane and parallel to said pivot axis of said joint, said second plane further being defined by said point on said first cutting edge, and at least one point on said first concrete crushing portion which lies in said second plane and is directed toward said second jaw, is positioned ahead of said first plane in a direction defined by pivoting movement toward said second jaw, and a third plane is defined by the pivot axis of said joint and a point on said second cutting edge, a fourth plane is perpendicular to said third plane and parallel to said pivot axis of said joint and defined by said point of said second cutting edge, whereby at least one point on said second concrete crushing portion which lies in said fourth plane and is directed toward said first jaw is positioned ahead of said third plane in a direction defined by pivoting toward said first jaw. 
     
     
       9. The concrete crushing tongs of claim 1, said first concrete crushing portion having first projections projecting towards said second jaw, said first projections including two corner projections positioned at respective corners of said frame-shaped first base body opposite said joint and projecting towards said second jaw, said second jaw having a first portion fitting into said interior space of said first jaw, and projections projecting towards said first jaw provided proximate to an outer edge of said first portion of said second concrete crushing portion. 
     
     
       10. The concrete crushing tongs of claim 3, wherein said first and second concave portions and said first and second projections are arranged relative to each other and relative to said first and second cutting edges such that upon closing said jaws together, said second jaw fits into said first jaws, cutting a reinforcement provided in a cutting sector defined by at least two projections of one of the jaws and two corresponding concave portions on either of said jaws, said reinforcement substantially severed before any further reinforcements are cut, as the jaws are closed together. 
     
     
       11. The concrete crushing tongs of claim 3, wherein said first and second concave portions each have a steadily curved shape, whereby, upon closing said jaws together, said concave portions and projections cooperate to fan out said reinforcement such that individual reinforcement strings running parallel to the pivot axis are aligned substantially side-by-side in one cutting sector in a direction perpendicular to the pivot axis, and a distance between two adjacent projections at one of said jaws in said direction perpendicular to said pivot axis, decreases in substantially inversely proportional manner with a distance between a point of contact of said first or second envelope and said first or second concave portions defined by said adjacent projections and said pivot axis.